Full Screen mode is widely used in programs such as Word, VisualC, Corel Draw etc. If you take a closer look on the these implementations you will notice that they solve this problem differently.
Below you will find an example for this problem. I have used it in my editor program ( MyLight ) for a long time. This application has been tested under Windows 9x and Windows NT.
So use it if you like. The only thing I recommend is that name me in your product.